Plastics have replaced many natural materials such as metal, wood, rope and glass due to their low cost, light weight, convenience, flexibility, and versatility. However, using plastic is not without drawbacks. It does not breakdown
readily and when scratched, heated or exposed to acidic substances, plastics release chemicals. Over time, plastics disintegrate into ever smaller fragments that ultimately enter the food chain. In 2005, 25 million tons of plastic were produced in the U.S. alone. Much is regarded as “disposable.” It is well known that between Japan and California, ocean currents are amassing a vast cesspool of plastic waste more than twice the size of Texas that is killing or poisoning sea birds and marine life.
readily and when scratched, heated or exposed to acidic substances, plastics release chemicals. Over time, plastics disintegrate into ever smaller fragments that ultimately enter the food chain. In 2005, 25 million tons of plastic were produced in the U.S. alone. Much is regarded as “disposable.” It is well known that between Japan and California, ocean currents are amassing a vast cesspool of plastic waste more than twice the size of Texas that is killing or poisoning sea birds and marine life.
Human Health Impacts. Links to developmental and reproductive abnormalities, cancers and neurological problems exist in animals and humans. So, which plastics are safe for baby bottles, water and food storage, children’s toys, and dental materials? The jury is still out on such questions but at least the recycling movement has won the use of a 7-point resin identification code in the chasing-arrows triangle embossed on most plastic containers.
Bad Plastics and Better Plastics #7, #3 and #6 are bad for our health. #7 (polycarbonate) is clear, rigid, and has been used for baby bottles, drinking cups and many one- and five-gallon water jugs. These plastics contain bisphenol A (BPA), an estrogenic chemical known to disrupt hormones in lab animals, especially in the growing fetus. BPA leaches out when the plastic is heated, exposed to acidic solutions, or after prolonged use. #3 (polyvinyl chloride or PVC) releases dioxins during both manufacture and incineration, and can also leach adipates and phthalates that cause birth defects and can damage many organs. PVC is virtually unrecyclable. PVC cling wrap is used to wrap deli cheeses and meats. #6 (polystyrene) leaches styrene and is another hormone disruptor and suspected human carcinogen. This chemical appears in foam cups and take-out containers, as well as plastic cutlery. These items should never be heated, such as in a microwave oven.
#1, #2, #4 and #5 are better, but not entirely free from suspicion. Smaller drink containers are made from #1 (polyethylene terephthalate or PET) or #2 HDPE. Research indicates that mineral water stored in PET bottles over time increases in estrogenicity. In another study, snails reared in plastic or glass bottles showed a higher reproductive rate and produced more embryos. Though not conclusive, these new findings add PET to the list of harmful contaminants for man and nature.3 #4 LDPE used in some plastic wraps, baggies, and baby bottle liners and #5 (polypropylene),used for reusable food containers, yogurt, and margarine tubs are blame-free -- for the moment!
Plastics in the News. Last year researchers reviewed BPA levels in 1,455 Americans from 18 to 74, and found higher levels of BPA in those with cardiovascular disease or diabetes.4 In June 2008, Canada became the first country to label BPA as toxic in an unprecedented “precautionary action to reduce exposure and increase safety.”5 This March, Playtex, Gerber, Evenflo and others stopped marketing polycarbonate baby bottles in the US.6 The same article states BPA has been found in various dental sealants and composites, and expresses concern that the FDA is not responding to the advice of its scientific advisors about the use of this chemical. In August the FDA stated that consumers should not discontinue use of products containing BPA, but suggested people use glass if concerned.7 BPA has been recently tied to aggression and hyperactivity in two-year old girls after detection of PBA in urine samples from their mothers during pregnancy.8 Lastly, little boys appear to be growing breasts as a result of exposure to phthalates used to soften plastics in toys and other products. Levels were 2.8 to 25 times higher in boys with enlarged breasts.
The Bottom Line. All plastics can leach chemicals under certain conditions. Don’t overheat even the most durable ones, that is, don’t put them in the microwave or dishwasher, don’t fill them with hot drinks, or leave them in a hot car or in hot sunlight. “Microwave safe” simply means the plastic won’t melt, but it may still release chemicals. Discard plastic items that are scratched or pitted. The safest choice are materials with a proven safety record: glass, oven-proof ceramic, and 18/8 stainless steel (18% chromium : 8 % nickel.)10 The good news is that more “green” plastics are coming! Polylactide is a corn-based polymer that can be commercially composted and takes 25 to 55percent less fossil fuels to produce and this product is already in use.
1. Oprah shines light on Great Pacific Garbage Patch [video]. (2009-04) http://tinyurl.com/cmqtvb2. Plastic recycling codes. http://tinyurl.com/835lbx 3. “More bad news about plastic containers?” (2009-05-15) N. Lubick. Environmental Science & Technology: 3406.4. ‘New study links plastic chemical to health risks. “(2008-09-17) J.C. Dooren. Wall Street Journal: D6. http://tinyurl.com/y9892ps5. “Canada moves to protect babies from chemical.” (2008-06-21) P. Webster. Lancet: 2074.6. “Bisphenol A (BPA): In our environment, food and dental restorations.” (2009-04) R. Krajac-Salva. Access: 22.7. Bisphenol A (PBA): Message for Consumers. http://tinyurl.com/ya4d4ku8. Plastics chemical tied to aggression in young girls. (2009-10-06) S. Gordon. http://tinyurl.com/ya6ysy39. Breast growth in boys might be linked to plastics chemical. R. Dotinga. http://www.wsfa.com/Global/story.asp?S=1168135610. Stainless steel water bottles information. http://stainlesssteelwaterbottles.info/ 11. Plastics graduate to green. (2006-04-06) P. McRandle. http://tinyurl.com/yck3oxm
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